Starter Inhibitor Switch Electrical Conniction

[CJHenderson]

Attached is several photos of my switch and electrical connector. The switch has six pins and my connector has only four female sockets on my new harness, I seem to remember that the old connector having six females. Do I have to build an add in for the other two?

[Pawel66]

There are four wires there coming out of that plug.

You have the wiring here, just scroll down the page a bit: https://www.sl113.org/wiki/Automatic/Start

The switch is component 51. It sends power to starter if R and N is selected and to the reverse light when R is selected. Two power sources (ignition switch and fuse box) and two receivers.

[WRe]

... or here
https://www.sl113.org/forums/index.php?topic=27083.msg194119#msg194119
...WRe

[CJHenderson]

Found my old photos and ran across several shots of the switch, the model that I have is a 70 280SL/8. It appears that I do not have the electrical schematic or wiring harness that relates to the 280sl/8.

[BobH]

Hello, the four connections that are shown in the schematics are all you need for starting and reverse lights, unless your emission system is still in use.  If it is then the other two connections are shown on the link below.  The neutral safety switch is called a "starter locking and backup light switch" on the first schematic, number 14, and number 48 on the 2nd schematic

https://www.sl113.org/wiki/Electrical/EmissionControlSystem

I'm not familiar with the emission system, but If you need to connect to it, you'll probably need to change the plug to a 6 way unit and run the other two wires

I must admit when owners change their wiring harness, i never understand how they get the correct one, with so many changes to the cars over the years and different variants, 230, 250, 280, LHD, RHD,  European, US, emission system, manual, auto etc etc

Good luck!

[CJHenderson]

It does have the emission system, next question can I delete it since my new harness does not look like it has the connections?

[BobH]

All i can suggest is you do a general search, i found this post

https://www.sl113.org/forums/index.php?topic=14228.msg96974#msg96974

Hopefully someone who has removed their system will reply with advice

[WRe]

Hi,
since this topic keeps coming up, I tried to bring things together. I hope it works that way.
...WRe

[BobH]

That's very useful, i've added it to the tech manual

[CJHenderson]

Thanks for all of the great help and advice, but unfortunately the new wiring harness doesn't have the connections for either of the 6 and 8 pin modules. When I ordered the LHD USA wire harness for the late 280SL would be missing some connection. Either I go without the emission system or order another harness. Bummer!!!!!!!!!!

[Pawel66]

Consult with lpeterssen. I think he may help.

[CJHenderson]

That is a good idea. I'm sure that he could build an addon harness.

[lpeterssen]

Dear Mr. Henderson

I certainly can build one emission control harness based on the wiring diagrams published somewhere else on this forum.  I did rebuilt one of them this year for another member which signs as “ Robouch8828”. That was a manual transmission late 70’ pagoda with emissions control system.  The harness was later installed by our friend Jo Alexander.

I will need you to send me a picture of the speed box and relay box terminals to make sure are equal the connector shape as the one published on this forum. Do that directly per email.  Will send you a PM.

I have to study in deep the diagram before building the system.

Best regards
Eng. L.Peterssen

[CJHenderson]

Thanks will do

[lpeterssen]

Dear friends

Working on the estimate for our hobby friend Mr. Henderson on the emission control harness for an auto car.

Do anyone knows what kind of terminal connector are used at the two oil pressure switches that are part of the system, circled in green on photo attached below?

Best regards
L.Peterssen

[BobH]

Hello Leo, does this help? there are some pictures on here, just eyelet connections if these are the correct switches

https://www.sl113.org/forums/index.php?topic=9029.0

[lpeterssen]

Hello Bob

Thanks for the link but I think is not the same thing.  Nevertheless, is a good clue that connectors in that place should be eyelet style.

But the link you sent me is for the regular connections of an automatic transmission, which has one IDDLE switch terminal, one for ground, and another for the kickdown switch response.

The connections shown on picture circled in green are two separated pressure switches.  They are not the connections of the automatic transmission selenoid terminal.

Will continue doing my Sherlock Holmes investigation.


Best regards
L.Peterssen

[BobH]

Hello Leo, i understood that these are the same switches, they are just wired differently in a car with emission control, they would still need eyelet connections?

[lpeterssen]

Yes they would have the same type of connections

[CJHenderson]

Here are the photos of the units that do not have connectors.

[lpeterssen]

Thank you very for the photos Mr Henderson

Studying diagrams……  almost finished.  Will continue later this afternoon, now I have to do some errands

Best regards
L.Peterssen

[lpeterssen]

Hello Leo, i understood that these are the same switches, they are just wired differently in a car with emission control, they would still need eyelet connections?

I am not yet convinced that are the same sensors, since all connections at the automatic transmission two position selenoid are positive signals, except 1 which feeds the IDDLE INCREASE SELENOID

The automatic transmission on a car without ECS the following lines:

1. IN: Ground, brown cable, big eyelet terminal
2. IN: Brown/black = kickdown (+) signal
3. IN: Brown/white = (+) signal coming from IDDLE SWITCH at intake manifold
4. OUTPUT: GREEN/RED which sends a (-) NEGATIVE signal to the IDDLE INCREASE SELENOID, APARENTLY when the VORNE (DRIVE) or RUECKWARDS (REVERSE) pressure switches trigger.   This maybe are the pressure switches that describe the EMISSION CONTROL SYSTEM diagram…….

SO….. If that is the case the two pressure switches described on the ECS end on this same port at the transmission that has the GREEN/RED line

Thank you very much for helping me solve this Sherlock a Holmes mistery….


Best regards
LP

[CJHenderson]

Also, I do not have either connection for the 17-degree switch or the 100-degree switch. I ordered this harness through SLS, I had no clue that all I was getting was just the most basic harness for my 280SL.

[BobH]

I am not yet convinced that are the same sensors, since all connections at the automatic transmission two position selenoid are positive signals, except 1 which feeds the IDDLE INCREASE SELENOID

The automatic transmission on a car without ECS the following lines:

1. IN: Ground, brown cable, big eyelet terminal
2. IN: Brown/black = kickdown (+) signal
3. IN: Brown/white = (+) signal coming from IDDLE SWITCH at intake manifold
4. OUTPUT: GREEN/RED which sends a (-) NEGATIVE signal to the IDDLE INCREASE SELENOID, APARENTLY when the VORNE (DRIVE) or RUECKWARDS (REVERSE) pressure switches trigger.   This maybe are the pressure switches that describe the EMISSION CONTROL SYSTEM diagram…….

SO….. If that is the case the two pressure switches described on the ECS end on this same port at the transmission that has the GREEN/RED line

Thank you very much for helping me solve this Sherlock a Holmes mistery….


Best regards
LP

Some more information on the ECS connections on this post, as i said earlier in this post, there are so may variables with wiring looms!

https://www.sl113.org/forums/index.php?topic=33631.msg245991#msg245991

[CJHenderson]

After reading all of the great posts on this problem that I'm facing, my 280SL/8 is without a doubt a very late 280SL and it appears what was sent to me was a wiring harness for an early
280SL. Then to have to make an addon harness which in the end will have cost me over $2500 dollars. So, with that in mind I'm thinking just to wrap this harness up and sell it on Ebay and turn around and reorder it from another harness company based in the US this time.